feat(deno): Add maxRequestBodySize to capture HTTP bodies - #22912

…#24233)

- [x] If you've added code that should be tested, please add tests.
- [x] Ensure your code lints and the test suite passes (`yarn lint`) &
(`yarn test`).
- [x] Link an issue if there is one related to your pull request. If no
issue is linked, one will be auto-generated and linked.

Ports the Deno body capture from #22912 to `Bun.serve`. Same
`maxRequestBodySize` option, same default (`medium` when `httpBodies`
includes `incomingRequest`, otherwise `none`), GET skipped, body read
before `continueTrace` so it lands on the request data. As on Deno an
explicit `maxRequestBodySize` wins over `httpBodies` in both directions.

One side effect: `normalizedRequest` now comes from
`winterCGRequestToRequestData`, so `query_string` loses the leading `?`
and is `undefined` instead of `""` when there is no query. That matches
what Deno, Cloudflare and Node already send, and the `url.query` span
attribute Bun was already stripping.

The body read is awaited before the handler runs and core caps it at 2s,
so a client that opens an upload and stalls holds the handler up to 2s
even if the handler never reads the body. Same as Deno and Cloudflare,
just new for Bun.

The isolation scope callback had to go async for the body read, so the
wrapper returns a promise now. `Bun.serve` accepts either, and every non
HEAD/OPTIONS path was already returning one via `startSpan`.

Tests: 10 new in `bunserver.test.ts`, 60/60 green for the package, plus
a `request-bodies` suite in `bun-integration-tests`, 14/14 green.

Closes #23884

AI disclosure: AI assistance (Claude) was used for research and to draft
the tests. The implementation was written and reviewed by the author.